227 research outputs found
Porcine Colostrum Protects the IPEC-J2 Cells and Piglet Colon Epithelium against Clostridioides (syn. Clostridium) difficile Toxin-Induced Effects
Clostridioides difficile toxins are one of the main causative agents for the clinical symptoms observed during C. difficile infection in piglets. Porcine milk has been shown to strengthen the epithelial barrier function in the pigletâs intestine and may have the potential to neutralise clostridial toxins. We hypothesised that porcine colostrum exerts protective effects against those toxins in the IPEC-J2 cells and in the colon epithelium of healthy piglets. The IPEC-J2 cells were treated with either the toxins or porcine colostrum or their combination. Analyses included measurement of trans-epithelial electrical resistance (TEER), cell viability using propidium iodide by flow cytometry, gene expression of tight junction (TJ) proteins and immune markers, immunofluorescence (IF) histology of the cytoskeleton and a TJ protein assessment. Colon tissue explants from one- and two-week-old suckling piglets and from five-week-old weaned piglets were treated with C. difficile toxins in Ussing chamber assays to assess the permeability to macromolecules (FITC-dextran, HRP), followed by analysis of gene expression of TJ proteins and immune markers. Toxins decreased viability and integrity of IPEC-J2 cells in a time-dependent manner. Porcine colostrum exerted a protective effect against toxins as indicated by TEER and IF in IPEC-J2 cells. Toxins tended to increase paracellular permeability to macromolecules in colon tissues of two-week-old piglets and downregulated gene expression of occludin in colon tissues of five-week-old piglets (p = 0.05). Porcine milk including colostrum, besides other maternal factors, may be one of the important determinants of early immune programming towards protection from C. difficile infections in the offspring
In good times and in bad: How plasma cells resolve stress for a life-long union with the bone marrow
In good times and in bad: How plasma cells resolve stress for a life-long union with the bone marrow
Die Bedeutung der auĂenwirtschaftlichen AktivitĂ€ten fĂŒr den deutschen Mittelstand: Untersuchung im Auftrag des Bundesministeriums fĂŒr Wirtschaft und Technologie
Das Institut fĂŒr Mittelstandsforschung (IfM) Bonn hat in Kooperation mit dem Volkswirtschaftlichen Institut fĂŒr Mittelstand und Handwerk an der UniversitĂ€t Göttingen (ifh) im Auftrag des Bundesministeriums fĂŒr Wirtschaft und Technologie (BMWi) eine Studie zu den AuslandsaktivitĂ€ten mittelstĂ€ndischer Unternehmen durchgefĂŒhrt. Ziel der Studie war es, den Anteil der mittelstĂ€ndischen Unternehmen am deutschen Export und Import von GĂŒtern und Dienstleistungen und dessen Entwicklung in den letzten fĂŒnf Jahren getrennt nach Branchen, Regionen und UnternehmensgröĂe zu ermitteln. Zudem sollte die Auswirkung auf die BeschĂ€ftigung dargestellt und der Anteil der deutschen Wertschöpfung der exportorientierten mittelstĂ€ndischen Unternehmen bestimmt werden. An der Befragung beteiligten sich mehr als 500 mittelstĂ€ndische Unternehmen. ZusĂ€tzlich wurden 94 Expertenmeinungen eingeholt. --
In the Right Place, at the Right Time: Spatiotemporal Conditions Determining Plasma Cell Survival and Function
Plasma cells (PCs), the B lineage cells responsible for producing and secreting antibodies (Abs), are critical cellular components of the humoral immune system. While most of the antibody-secreting cells in the body have a rather short lifetime of a few days, some of them can become long-lived and persist in the body over the entire life span of an individual. The majority of these long-lived plasma cells secretes protective antibodies against pathogens, and are thereby crucial for the humoral component of immunological memory. The generation of these protective antibody-secreting cells can be triggered by an exposure to pathogens, and also by vaccination. Although the majority of plasma cells are protective, sometimes long-lived plasma cells produce autoreactive antibodies, which contribute to the pathogenesis and perpetuation of chronic autoimmune diseases, including lupus erythematosus, rheumatoid arthritis, or multiple sclerosis. In order to promote the formation of protective antibody-secreting cells and to target pathogenic plasma cells, it is crucial to understand the signals which promote their longevity and allow them to exert their function. In recent years, it has become clear that plasma cells depend on extrinsic factors for their survival, leading to the concept that certain tissue microenvironments promote plasma cell retention and longevity. However, these niches are not static structures, but also have dynamic features with respect to their cellular composition. Here, we review what is known about the molecular and cellular composition of the niches, and discuss the impact of dynamic changes within these microenvironments on plasma cell function. As plasma cell metabolism is tightly linked to their function, we present new tools, which will allow us to analyze metabolic parameters in the plasma cell niches in vivo over time
Analyzing nicotinamide adenine dinucleotide phosphate oxidase activation in aging and vascular amyloid pathology
In aging individuals, both protective as well as regulatory immune functions
are declining, resulting in an increased susceptibility to infections as well
as to autoimmunity. Nicotinamide adenine dinucleotide phosphate (NADPH)
oxidase 2-deficiency in immune cell subsets has been shown to be associated
with aging. Using intravital marker-free NAD(P)H-fluorescence lifetime
imaging, we have previously identified microglia/myeloid cells and astrocytes
as main cellular sources of NADPH oxidase (NOX) activity in the CNS during
neuroinflammation, due to an overactivation of NOX. The overactivated NOX
enzymes catalyze the massive production of the highly reactive Oâ2, which
initiates in a chain reaction the overproduction of diverse reactive oxygen
species (ROS). Age-dependent oxidative distress levels in the brain and their
cellular sources are not known. Furthermore, it is unclear whether in age-
dependent diseases oxidative distress is initiated by overproduction of ROS or
by a decrease in antioxidant capacity, subsequently leading to
neurodegeneration in the CNS. Here, we compare the activation level of NOX
enzymes in the cerebral cortex of young and aged mice as well as in a model of
vascular amyloid pathology. Despite the fact that a striking change in the
morphology of microglia can be detected between young and aged individuals, we
find comparable low-level NOX activation both in young and old mice. In
contrast, aged mice with the human APPE693Q mutation, a model for cerebral
amyloid angiopathy (CAA), displayed increased focal NOX overactivation in the
brain cortex, especially in tissue areas around the vessels. Despite activated
morphology in microglia, NOX overactivation was detected only in a small
fraction of these cells, in contrast to other pathologies with overt
inflammation as experimental autoimmune encephalomyelitis (EAE) or
glioblastoma. Similar to these pathologies, the astrocytes majorly contribute
to the NOX overactivation in the brain cortex during CAA. Together, these
findings emphasize the role of other cellular sources of activated NOX than
phagocytes not only during EAE but also in models of amyloid pathology.
Moreover, they may strengthen the hypothesis that microglia/monocytes show a
diminished potential for clearance of amyloid beta protein
Low-Density Granulocytes Are a Novel Immunopathological Feature in Both Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder
Objective: To investigate whether low-density granulocytes (LDGs) are an immunophenotypic feature of patients with multiple sclerosis (MS) or neuromyelitis optica spectrum disorder (NMOSD).
Methods: Blood samples were collected from 20 patients with NMOSD and 17 patients with MS, as well as from 15 patients with Systemic Lupus Erythematosus (SLE) and 23 Healthy Donors (HD). We isolated peripheral blood mononuclear cells (PBMCs) with density gradient separation and stained the cells with antibodies against CD14, CD15, CD16, and CD45, and analyzed the cells by flow cytometry or imaging flow cytometry. We defined LDGs as CD14-CD15(high) and calculated their share in total PBMC leukocytes (CD45+) as well as the share of CD16(hi) LDGs. Clinical data on disease course, medication, and antibody status were obtained.
Results: LDGs were significantly more common in MS and NMOSD than in HDs, comparable to SLE samples (median values HD 0.2%, MS 0.9%, NMOSD 2.1%, SLE 4.3%). 0/23 of the HDs, but 17/20 NMOSD and 11/17 MS samples as well as 13/15 SLE samples had at least 0.7 % LDGs. NMOSD patients without continuous immunosuppressive treatment had significantly more LDGs compared to their treated counterparts. LDG nuclear morphology ranged from segmented to rounded, suggesting a heterogeneity within the group.
Conclusion: LDGs are a feature of the immunophenotype in some patients with MS and NMOSD
Ongoing Oxidative Stress Causes Subclinical Neuronal Dysfunction in the Recovery Phase of EAE
Most multiple sclerosis (MS) patients develop over time a secondary
progressive disease course, characterized histologically by axonal loss and
atrophy. In early phases of the disease, focal inflammatory demyelination
leads to functional impairment, but the mechanism of chronic progression in MS
is still under debate. Reactive oxygen species generated by invading and
resident central nervous system (CNS) macrophages have been implicated in
mediating demyelination and axonal damage, but demyelination and
neurodegeneration proceed even in the absence of obvious immune cell
infiltration, during clinical recovery in chronic MS. Here, we employ
intravital NAD(P)H fluorescence lifetime imaging to detect functional NADPH
oxidases (NOX1â4, DUOX1, 2) and, thus, to identify the cellular source of
oxidative stress in the CNS of mice affected by experimental autoimmune
encephalomyelitis (EAE) in the remission phase of the disease. This directly
affects neuronal function in vivo, as monitored by cellular calcium levels
using intravital FRETâFLIM, providing a possible mechanism of disease
progression in MS
Spatial Distribution of Macrophages During Callus Formation and Maturation Reveals Close Crosstalk Between Macrophages and Newly Forming Vessels
Macrophages are essential players in the process of fracture healing, acting by remodeling of the extracellular matrix and enabling vascularization. Whilst activated macrophages of M1-like phenotype are present in the initial pro-inflammatory phase of hours to days of fracture healing, an anti-inflammatory M2-like macrophage phenotype is supposed to be crucial for the induction of downstream cascades of healing, especially the initiation of vascularization. In a mouse-osteotomy model, we provide a comprehensive characterization of vessel (CD31+, Emcn+) and macrophage phenotypes (F4/80, CD206, CD80, Mac-2) during the process of fracture healing. To this end, we phenotype the phases of vascular regeneration-the expansion phase (d1-d7 after injury) and the remodeling phase of the endothelial network, until tissue integrity is restored (d14-d21 after injury). Vessels which appear during the bone formation process resemble type H endothelium (CD31hiEmcnhi), and are closely connected to osteoprogenitors (Runx2+, Osx+) and F4/80+ macrophages. M1-like macrophages are present in the initial phase of vascularization until day 3 post osteotomy, but they are rare during later regeneration phases. M2-like macrophages localize mainly extramedullary, and CD206+ macrophages are found to express Mac-2+ during the expansion phase. VEGFA expression is initiated by CD80+ cells, including F4/80+ macrophages, until day 3, while subsequently osteoblasts and chondrocytes are main contributors to VEGFA production at the fracture site. Using Longitudinal Intravital Microendoscopy of the Bone (LIMB) we observe changes in the motility and organization of CX3CR1+ cells, which infiltrate the injury site after an osteotomy. A transient accumulation, resulting in spatial polarization of both, endothelial cells and macrophages, in regions distal to the fracture site, is evident. Immunofluorescence histology followed by histocytometric analysis reveals that F4/80+CX3CR1+ myeloid cells precede vascularization
Vaccination with virosomally formulated recombinant CyRPA elicits protective anti against Plasmodium falciparum parasites in preclinical in vitro and in vivo modelsbodies
The; Plasmodium falciparum; (; Pf; ) cysteine-rich protective antigen (; Pf; CyRPA) has emerged as a promising blood-stage candidate antigen for inclusion into a broadly cross-reactive malaria vaccine. This highly conserved protein among various geographical strains plays a key role in the red blood cell invasion process by; P. falciparum; merozoites, and antibodies against; Pf; CyRPA can efficiently prevent the entry of the malaria parasites into red blood cells. The aim of the present study was to develop a human-compatible formulation of the; Pf; CyRPA vaccine candidate and confirming its activity in preclinical studies. Recombinant; Pf; CyRPA expressed in HEK 293 cells was chemically coupled to phosphoethanolamine and then incorporated into the membrane of unadjuvanted influenza virosomes approved as antigen delivery system for humans. Laboratory animals were immunised with the virosome-based; Pf; CyRPA vaccine to determine its immunogenic properties and in particular, its capacity to elicit parasite binding and growth-inhibitory antibodies. The vaccine elicited in mice and rabbits high titers of; Pf; CyRPA-specific antibodies that bound to the blood-stage parasites. At a concentration of 10 mg/mL, purified total serum IgG from immunised rabbits inhibited parasite growth in vitro by about 80%. Furthermore, in a; P. falciparum; infection mouse model, passive transfer of 10 mg of purified total IgG from; Pf; CyRPA vaccinated rabbits reduced the in vivo parasite load by 77%. Influenza virosomes thus represent a suitable antigen delivery system for the induction of protective antibodies against the recombinant; Pf; CyRPA, designating it as a highly suitable component for inclusion into a multivalent and multi-stage virosomal malaria vaccine
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